Method of treating photographic sheet with a liquid



E. H. LAND Aug. 17, 1965 METHOD OF TREATING PHOTOGRAPHIC SHEET WITH ALIQUID 3 Sheets-Sheet 1 Filed Feb. 15, 1962 INVENTOR.

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ATTORNEYS E. H. LAND Aug. 17, 1965 Filed Feb. 15, 1962 Aug. 17, 1965 E.H. LAND 3,200,726

METHOD OF TREATING PHOTOGRAPHIC SHEET WITH A LIQUID Filed Feb. 15, 19623 Sheets-Sheet 3 INVENTOR.

EMH4- ATTORNEYS United States Patent sesame METHOD OF TREATINGPHQTUGRAPHHC SHEET WITH A LIQUID Edwin H. Land, Cambridge, Mass assignorto Polaroid Corporation, (Iambridge, Mass., a corporation of DelawareFiied Feb. 15, 1962, Ser. No. 173,496

8 Claims. (CI. 95-43) This invention relates to photographic processesand particularly to a photographic process in which a sheet is treatedwith a liquid distributed in a layer on said sheet.

A number of photographic processes are performed by superposing a pairof sheets and distributing a processing liquid in a layer between thesuperposed sheets. Many of these processes employ a photographicimage-recording sheet and are performed in photographic apparatus suchas a camera in which the image-recording sheet is photographicallyexposed and processed to produce a visible image. The processing liquidmay be distributed between the sheets by movement of the sheets alongconvergent paths into superposition between a pair of-juxtaposed memberswhile a fluid is introduced between the sheets through a suitable nozzlesuch as is disclosed in copending US. application Serial No. 159,234,filed December 14, 1961, in the name of Edwin H. Land, now Patent No.3,142,243, issued July 28, 1964. The liquid is usually supplied to thenozzle under pressure and disrtributed by moving the sheets past thenozzle between the juxtaposed members. the apparatus to effect exposureand processing of successive areas of the image-recording sheet isaccomplished by engaging at least one of the sheets either manually orby some means (e.g. rolls) and drawing the sheets befi l/631 thejuxtaposed members (which may be driven ro s The invention has as anobject, the provision of a novel and improved photographic process inwhich a pair of photographic sheets are advanced through photographicapparatus into superposition between a pair of juxtaposed members; aprocessing liquid is distributed between the superposed sheets, and thefluid is introduced between the sheets through a nozzle in such a way asto effect the movement of the sheets through the apparatus and betweenthe juxtaposed members.

Other objects of the invention are: to provide a photographic process asdescribed in which the energy required to perform the process, i.e., tomove the sheets and distribute the fluid, is initially imparted to thefluid and is transferred thereby to the sheets; and to provide aphotographic process as described in which the energy required toperform the process is imparted to the fluid by the container in whichthe fluid is supplied.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the process involving the severalsteps and the relation and order of one or more of such steps withrespect to each of the others which are exemplified in the followingdetailed disclosure, and the scope of the application of which will beindicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings wherein:

FIGURE 1. is a sectional view, of photographic paratus in the form of acamera for of the invention;

FIG. 2 is a perspective view, partially in section, illustratingcomponents of the apparatus of FIGURE 1;

FIGS. 3 and 4 are somewhat schematic, sectional views appracticing themethod Movement of the sheets through 3,269,726 Patented Aug. 17, 1965 2illustrating the operation of components of the apparatus of FIGURE 1;

FIG. 5 is a sectional view of shown in FIG. 2;

FIG. 6 is a fragmentary perspective view of other components of theapparatus of FIGURE 1; and

FIG. 7 is a view similar to FIG. 3 of another embodiment of means forpracticing the invention.

In photographic processes of the type with which the present inventionis concerned, a photographically exposed, photosensitive image-recordingsheet comprising, for example, a gelatino silver halide emulsion layercarried on a support, is guided into superposition with a second sheetincluding, for example, a layer for supporting a silver transfer image,between a pair of juxtaposed pressure-applying members. As the twosheets are moved along convergent paths into superposition at, andbetween, the juxtaposed members, a processed liquid capable, forexample, of effecting a silver halide diffusion-transfer reversalprocess and including a silver halide developer and a silver halidesolvent, is introduced through a nozzle between the sheet at thepressure-applying members which cooperate with the nozzle and sheets todistribute the liquid in a layer between the sheet. Apparatus forperforming such processes may comprise, in addition to means fortreating the image-recording sheet with the liquid, means for exposingthe sheets; and heretofore it has been a practice to advance the sheetsthrough the apparatus by engaging the sheets and drawing them be tweenthe juxtaposed pressure-applying members. Engagement and advancement ofthe sheets may be accomplished manually as in currently available handheld cameras of the type produced by Polaroid Corporation; or may beeffected by mechanical means such as rollers which engage the sheets andare driven to advance the sheets through the apparatus. In apparatus andprocesses in which the liquid for treating a succession of exposed areasof the image-recording sheet is supplied from a single container anddispensed by a single nozzle, the apparatus includes, in addition tomeans for advancing the sheets, means for feeding the liquid to thenozzle under pressure, means for coordinating fluid feeding and sheetadvancement, and means for controlling sheet advancement, i.e., indexingmeans, insuring exposure and processing of predetermined successiveareas of the image-recording sheet.

The invention represents a novel and improved method of advancing thesheets through the apparatus in which the means for feeding the liquidto the nozzle under pres sure, the nozzle and the liquid itself providethe means and the motive power for advancing the sheets, while controlof sheet advancement (indexing) is effected by controlling the flow ofthe liquid to the sheets. In the copending US. application of Edwin H.Land, Serial No. 169,264, filed January 29, 1962 (now abandoned), it isproposed that the energy required to feed the liquid to the nozzle underpressure be stored and imparted to the liquid by the container in whichthe liquid is supplied. The container in this instance would comprisesan elastomeric material in a stretched condition and makes possible theconcept envisioned by the present invention of apparatus such as acamera, the operation of which is substantially automatic and which ispowered by a container of processing liquid supplied with the sheetmaterials employed in the camera.

Reference is now made to FIGURE 1 of the drawings in which is shownphotographic apparatus in the form of a small, compact, handheld camera10 of a type in which the method of the invention is practiced. Cameraltlcomprises a housing including a forward wall 12, having a recessed orre-entrant section 14, extending rearwardly to an inner forward Wall 16,side walls 18, and a rear wall 20. The walls of the housing cooperaportion of the apparatus ate to provide chambers designated 22 and 2d atopposite ends of the housing, and an exposure chamber located betweeninner forward Wall in and rear wall 2%. Camera Ill includes aconventional lens and shutter assembly designated 26, coupled to thecamera by a bellows 28 joined to assembly and to inner forward 'wall 16,around the edges of an exposure aperture dd, provided in inner forwardwall lid for transmittinglight from the lens to a photographicimage-recording sheet positioned within the exposure chamber betweeninner forward wall 16 and rear wall 26% The bellows and the camerahousing are preferably constructed so that the shutter assembly can bedisplaced from the extended operative a position shown in FIGURE 1 to afolded or closed posi* tion at which the bellows is collapsed within therecess described, and the shutter assembly is also dispensed within therecess.

The photosensitive image-recording sheet herein designated 32 ispreferably supplied in a coiled condition on a spool 36 which is mountedfor rotation within chamber 22. The image-recording sheet extends fromchamber 252 at one end of inner forward wall 16, between the latter andthe rear wall2ti, across exposure aperture and the rear surface of wall15 to chamber 24 at the opposite end of the camera housing. The rear orinner surface of wall 16 is preferably located at the focal surface ofthe lens of assembly 2d and a guide and indexing roll 38 i providedwithin chamber 22 near the entrance to the exposure chamber for holdingsheet 32 in position for exposure against the rear surface of wall 16and performing other functions Whichwill be described hereinafter. 1

As previously indicated, the photosensitive image-recording sheet istreated, following exposure, with a liquid distributed between theimage-recording sheet and a second sheet superposed therewith. A supplyof this second sheet, designated 4%, is provided within chamber 24together with means in the form of a pair of juxtaposed members forsuperposing the photosensitive and second sheets and aiding in thedistribution of a processing liquid in a layer between the sheets. Inthe form shown, the

juxtaposed members comprise a pair of pressure-applying rolls 42' and44, mounted in juxtapositionwithin chamber 24, adjacent an end of wall16 near the entrance to the exposure chamber between wall 16 and rearwall 20. Image-recording sheet 32 is guided from spool 36 Within chamber22, between roll 33 and an end portion of inner forward wall 16, throughthe exposure chamber across exposure aperture 3d, and aroundpressure-applying roll 44 between rolls 42and 44 toward the rear of thecamera. Second sheet 4t extends within chamber 24 into superpositionwith image-recording sheet 32 at the bite of rolls 42 and 44- andextends in superposition with the image-recording sheet between thepressure-applying rolls. a An exit passage 46 is provided in rear wall29 in alignment with the gap between'rolls 42 and 44 to permit movementof sheets '32 and from the housing. The sheets, as shown, are guidedalong convergent paths into superposition at the bite of thepressure-applying rolls, and it is between the convergent portions ofthe sheets at the bite of the rolls that the fluidprocessing liquid isdispensed.

The'sheets and processing liquid maybe provided as part of a productshown in FIGS. 2 and 5 of the drawings as comprising, in addition toimage-recording sheet 32, spool 36 and second sheet 40, means in theform of a nozzle 43 for dispensing a processing liquid as a layerbetween the photosensitive and second sheets at the bite rubber aresuited for this purpose and include, for example, high densitypolyethylene, polypropylene, polyvinylidene chloride and polyethyleneterephthalate resins. The nozzle, shown in detail in FIGS. 3 and 4,includes an elongated generally cylindrical body section 5i? having endwalls 52 cooperating with the body to provide an elongated chamber 54within the body section and extending from end to end thereof. The bodysection is substantially rigid and is provided along one side with apair of thin flexible lips 56 extending substantially from end to end ofthe body section. End walls 52 include tapered portions cooperating withlips 56, which converge toward one another, to define a tapered passage58 between the lips coupled with chamber 54 and terminating at the edgesof the lips in a very narrow elongated discharge mouth til) throughwhich a liquid introduced into chamber 54 is dispensed. The materialcomprising lips 56 and end walls 52, and the construction of the lipsand the tapered portions of the end walls, are such that mouth 69 can besealed by the application of compressive pressure to the edge portionsof the lips. For details and a further description of nozzles similar tonozzle 43 and adapted to incorporation in a structure for practicing themethod of 'the invention, reference may be had to the aforementioned US.Patent No. 3,142,243.

In the form of product designed for performing the method of theinvention and shown in the drawings, the processing liquid is suppliedand stored under pressure in a container designated 66 comprising anelongated and generally cylindrical tube open'at one end, closed at itsother end, and having, in its unextended condition, an inside diametercomparable to its wall thickness and equal to a fraction of its outsidediameter. Corn I tainer dis formed of an elastomeric material such asnatural rubber (polyisoprene) or synthetic rubber (synthetic isoprene)and filled with the processing liquid under pressure so that the liquidmaintains the con tainer in a stretched and expanded condition while theelasticity of the material comprising the container causes pressure tobe exerted on the liquid. The container may be filled, and designed andconstructed in such a way as to dispense the liquid at a substantiallyconstant and predetermined pressure. For a more complete description ofthe container, its manner of assembly, and filling, and it function andoperation, reference may be had to the aforesaid copending U.S.Application Serial No. 169,264.

Container 66, in its fully expanded condition, is shown with its openend engaged around tube 68 and enclosed within a cylindrical tube 7!which serves to confine the container and protect the container fromdamage. Tube 76 also functions as a support around which second sheet 4%is coiled; and as means for retaining second sheet 40 in a coiledcondition on tube '75 there are provided enclosures 72 and 74 engaged inopposite ends of tube 76 and each having a flange 76 the diameter ofwhich is greater than the diameter of tube 70 and cooperates with thetube to define a spool on which the second sheet is coiled. Closure 74of tube 70 may be provided with an air vent (not shown), formed topermit the expansion and contraction of container 66 with 7 78. Theouter end of closure 72 is provided with an on of the pressure-applyingrolls, and means for holding a supply of the processing liquid,delivering the liquid to the nozzle under pressure and supporting thenozzle in proper position to perform its liquid-dispensing'function.Nozzle 48 ispreferably formed of a material which i is impervious to theliquid and to air and has some flexibility and resiliency. Variousorganic plastics and larged recess Sil separated from a recess 32defined by tube 68, by a dividing wall 84, and connected with recess 82by way of a relatively small bore 86 through wall 34. Recesses 8i and 32and bore 86am substantiallycylindrical and disposed coaxially, andclosure '72is designed to be formed as a single element of an organicplastic material such as employed to form nozzle 48. The a in thechamber defined by tube 7%) and closures 72 and valve comprises a valvemember 83 to which is attached a valve stem 95? extending from recess 32through bore 86 into recess 80 and having a shape and dimension whichpermit the flow of liquid through bore 8d around the valve stem. AnO-ring 92 is provided as a seal between valve member b8 and the surfaceof wall 84 at the periphery of bore 86; and inwardly projecting axialribs 9 3 are provided on the inner surface of tube 63 for guiding thevalve member for axial movement within recess 32 while permitting flowof the liquid around the valve member. Valve member 33 is biased intothe closed position shown in PEG. 5 by a coil spring 96, retained inrecess $2. by a retaining washer 98, engaged in a circum ferentialrecess in the inner surface of tube 68. As a means for displacing thevalve member to an open position and conducting the liquid from recess89 to the nozzle, there is provided a cap 100 having a skirt 102 engagedwithin recess and an end wall the including annular flexible section anda tube 1% connecting with recess 80. The end of valve stem 90 isenlarged and is engaged within recess at the center of end wall 104,while the annular flexible section permits the valve stem to bedisplaced inwardly by pressure on end wall 104 to open the valve andallow the liquid to How from recess 82 through bore 86 into recess lid.

Nozzle all is provided at one end with an Ls-haped tubular conduit 62communicating with chamber 54 for conducting the liquid into the chamberand for supporting one end of the nozzle. A similar tube or a solid rod64 is provided at the opposite end of nozzle 48 projecting from end wall52 for supporting the opposite end of the nozzle. Conduit d2 is engagedin tube 166 while rod 64 is engaged in a tube 1% extending from closure74 so that tubes 1% and 108 cooperate with conduit 62 and rod 64 formounting and supporting the nozzle in position for dispensing the fluidcontents of container 66 between the sheets at the bite of thepressure-applying rolls.

Nozzle a3 is mounted for operation with lips 56 extending toward thebite of the rolls between convergent portions of sheets 32 and 40 withthe outer surfaces of at least the edge portions of the lips located inface to face contact with the facing surfaces of the sheets. Rolls 42and 4d are movable between an operative, liquid-spreading position shownin FIG. 3, and an inoperative, nozzlesealing position shown in FIG. 4.In the operative, liquidspreading position of the rolls, the maximumwidth of the gap between the rolls at the narrowest portion of the gapis fixed and is approximately equal to the combined thicknesses of thetwo sheets and the layer of liquid to be distributed between the sheets.Lips 56 extend between the convergent portions of the sheets to aposition just short of the narrowest portion of the gap so that thewidth of mouth tilt is substantially equal to the thickness of the layerof liquid. The length of the mouth, i.e., the distance between end walls52, is preferably equal to the width of the area of the photosensitivesheet to be treated with the liquid.

The image-recording and second sheets are guided, as shown, around andbetween portions of pressure-applying rolls 42 and 44 through a gapbetween the rolls, and movement of the sheets through the apparatus intosuperposition between the rolls is accomplished by introducing theprocessing liquid through the nozzle between the sheets under sufficientpressure to cause the advancement of the sheets. In the operation ofcamera 10, an area of imagerecording sheet 52 positioned across aperture33 is exposed; and this area is then advanced into superposition with acorresponding areas of second sheet 40 between pressure-applying rolls42 and 4-4 while the processing liquid is distributed from nozzlethrough mouth 60 in a thin layer between the sheets to form a sandwich.Advancement of the sheets through the apparatus is continued until theexposed area has been advanced entirely between the pressure-applyingrolls and preferably from the camera and is then discontinued to permitthe next succeeding area of the photosensitive sheet to be exposedthrough aperture 30. The portion of the sandwich comprising thepreviously exposed area of the image-recording sheet may be severed fromthe remainder of the sandwich extending between rolls 42 and 44,preferably as close as possible to the rolls in order to conserve sheetmaterials.

The pressure on the liquid, in addition to advancing the sheets,obviously presses the lips outwardly against the sheets therebyefiectively preventing entrapment of air between the lips and the sheetsand escape of the processing liquid. The liquid, as previouslyindicated, is dispensed from mouth 65 substantially in the form of alayer which is immediately engaged between the opposed surfaces of thesheet and causes the movement of the sheets by pressing against thelayer of fluid engaged between the sheets. In order to facilitatemovement of the sheets by the liquid, the latter is preferably quiteviscous, having a viscosity at 24 centigrade in excess of 1,000centipoises and ranging from 1,000 to 200,000 centipoises. Theviscosity-causing ingredient may comprise, for example, sodiumcarboxymethyl cellulose which, as components (e.g., water) of the liquidare absorbed by the sheets, also functions in the nature of an adhesivefor maintaining the integrity of the sandwich comprising the two sheetsand layer of liquid and providing means against which the liquiddispensed from the nozzle can exert pressure for moving the sheets. Forthe details and for ulations of processing liquids suitable for use inthe method of the invention and particularly for effecting silverhalidediffusion transfer reversal processes, reference may be had to US.Patents Nos. 2,543,181, issued February 27, 1951, and 2,662,822, issuedDecember 15, 1953, both in the name of Edwin H. Land.

In a camera of the construction illustrated, when the camera is not inuse for treating an exposed area of the image-recording sheet with theliquid and the sheets are not being moved between the pressure-applyingrolls, the rolls are moved to their inoperative, nozzle-sealing positionat which the rolls compress the lips of the container toward one anotherso as to seal mouth 60. In this sealing action the rolls, as illustratedin FIG. 4, are displaced from the operative position of FIG. 3 in adirection opposite to the direction of movement of the sheets betweenthe rolls so that the edge portions of lips 55 are located within thebite of the rolls at the narrowest portion of the gap. As the rolls aredisplaced from operative to inoperative position in a direction oppositeto the direction of movement of the sheets and the flow of liquid andtoward the nozzle, the lips remain substantially stationary supported bybody section 50 of the nozzle; and the rolls may be displaced apartslightly so as to accommodate the combined thickness of the lips betweenthe sheets as this thickness maybe greater than the thickness of thelayer of fiuid and the gap between the sheets.

Camera 10 is operated to advance the sheets and treat an exposed area ofthe image-recording sheet with a liquid by opening valve 88 andsimultaneously moving the pressure-applying rolls into operative,fluid-spreading position. This opening of the valve and movement of therolls need be the only operation, except for tripping the shutter, thatthe operator must perform, the processing being otherwise automatic withthe apparatus being operated by the pressure on the fluid exertedthereon by the container. The camera includes a mechanism which may beactuated manually to open the valve and move the pressure-applying rollsinto operative, fluid-spreading position, and which is thereafteroperated in response to movement of the sheets through the apparatus forclosing the valve and moving the pressure-applying rolls intoinoperative, nozzle-sealing position and thereby arresting the movementof the sheets when a predetermined ex posed area of the photosensitivesheet has been treated with the processing fluid. This mechanismincludes means for mounting the rolls comprising a pair of arms 7 1111each mounted at one end on a pivot 112 secured to the camera housing,with roll 1-2 mounted for rotation at its ends on arms 11% intermediatetheir ends. Roll 44 is mounted at its ends near the free ends on a pairof levers 114, which are mounted for pivotal movement intermediate theirends on pivots 116 having a common axis and secured to the camerahousing. The free end of each of arms 1111 is pivotally connected at apivot 118 to the free end of one of levers 114 at a positionintermediate rolls 42 and 44. In the operative, fluid-spreading positionof rolls 4;? and id, the axes of therolis and pivots 112, 116, and 113lie substantially in a plane with the axis of pivot-s 118 being locatedequidistant from the axes of pivots 112 and 116 and the axes of rolls4?. and dd. This arrangement insures that any movement imparted to roll44 by levers 114 will be imparted to roll so that the latter willdescribe the same movement as roll 44 simultaneously with the movementof roll 44. A spring 1211 is provided coupled between each of levers 11dand the camera housing for biasing each lever (in a clockwise directionviewing FIG. 6) so as to bias rolls 4-2 and 4 for movement intoinoperative nozzle-sealing position.

Means are provided for retaining the pressure-applying rolls inoperative, fluid-spreading position and in theform shown comprise a pairof cams 122mounted on a shaft 124 and each located in engagement with anend section 125 of one of levers 114, which end section acts as acam'follower. Each of cams 12.2 is designed to coact with a lever 114 soas to pivot the lever in such a way as to position rolls 42 and 44 inthe operative position shown in FIG. 6. The mechanism for moving therolls and actuating the valve is operated in response to movement of thesheets through the apparatus and derives its motive power from'roll 38which is located in frictional engagement with the image-recording sheetso as to be rotated thereby during movement of the sheet through theapparatus. Roll 38 is provided with a gear (not shown) which is meshedwith a gear 128 keyed to shaft 124. The ratio or" the numbers of teethon the two gears is such that gear 128 is rotated through one revolution(360) in response to movement of an exposed area of the image-recordingsheet from exposure position, between the pressure-applying rolls andfrom the camera. Cams 122 are coupled with gear 123 through shaft 124,each of cams 122 being mounted on shaft 124 for limited movement withrespect to the shaft through a conventional spring devicewhich permitsshaft 124 to rotate through a few degrees while cams 122 are heldagainst rotation (in a clockwise direction viewing in FIG. 6); and whencam 122 is released for rotation, the spring will cause the cam torotate so as to catch up to the shaft. Each of cams 122 is designed tofunction as a sheetarresting mechanism, that is, to permit the rolls tomove into inoperative nozzle-sealing position each time a predeterminedlength of the image-recording sheet has moved through the apparatus.provided with an abrupt recess 13% into which end section 126 of lever114 moves under the bias of spring 126 when recess 1% comes intoalignment with the end section of the lever. This immediately stops therotation of the cam which in turn arrests the rotation of shaft 124 androll 38 at the end of a few more degrees of a revolution thereof andpermits the rolls to move into inoperative position under the bias ofsprings 121B.

aaeograe 538. The opposite end of lever 132 is in the form of a camfollower 13% positioned in engagement with a cam 14% secured to andcomprising a part of cam 122. Cam 1 1i) is designed to hold lever 132pivoted in such a position as to hold valve 33 open, and includes arecess 1 52, aligned with recess 13%, into which cam follower 133' mayproject permitting lever 132 to pivot in such a Way as to allow valve 38to close.

An operating or sheet-advancing cycle of the apparatus is commenced (andterminated) with end section 126 of each of levers 114 engaged in arecess 13% of a can 122 and with cam follower 13S engaged in recess 142of cam 1411. The camera includes a manually operated device for pivotinglevers 11 iand 132 so as to disengage the ends of the levers from therecess in the cams and simultaneously'open valve 88 and move rolls i2and 44 into operative, fluid-spreading position. This manually operatedmeans may also be coupled with the shutter so that only one element needbe actuated by the operator to both make an exposure and process theexposed area of the image-recording sheet. Upon disengagement of endsection 126 from recess 13% and cam follower 138 from recess 142,, thecams immediately rotate in a clockwise direction under the bias of thespring connecting the cams with shaft 124 thereby moving the recessesout of alignment with end sections 126 and cam follower 138, so that theend sections and cam followers cannot return to engagement in therecesses until the cams have completed a full revolution. The device(not shown) for pivoting levers 114 and 132 is designed to momentarilyengage and pivot the levers so that the levers are free to return totheir positions prior to pivotal movement, which return movement isprevented by the cams.

The form of liquid-dispensing nozzle shown and described herein isdesigned for intermittent operation in which the lips of the nozzle arepressed together to seal the nozzle when it is not in use. Because ofthe type of operation for which the nozzle is intended, the area ofcontact between the liquid within the nozzle and the convergent portionsof the sheets between the For this purpose, cam 122 is The mechanismalso includes means for opening valve 88 at the commencement of theprocessing cycle and close the valve simultaneously with the movement ofthe pressure-applying rolls into inoperative position at the end of aprocess cycle. This last-mentioned means includes a lever 132 pivotallymounted intermediate its ends on a pivot 13d mounted in fixed positionon the camera housing. One end, designated 13%, of lever 132 is designedto engage the center of end wall 1% for displacing the end wall andvalve stem so as to open valve sheets between the pressure-applyingmembers.

pressure-applying members is minimized and this restricts, to someextent, the force which can be applied to the sheets by the liquidtending to move the sheets through the apparatus. The pressure exertedby the liquid within the nozzle on the convergent portions of the sheetslocated between the pressure-applying members can be resolved intocomponents normal to the surfaces of the sheets and parallel with thesurfaces of the sheets, with the latter components tending to move theThe total force exerted on the sheets and tending to advance the sheetsis a function of the'area of the convergent portions of the sheets incontact with the liquid and, as already noted, the viscosity of theliquid.

Reference is now made to FIG. 7 of the drawings in which there isillustrated a nozzle designed for continuous, rather than intermittent,fluid distributing operation and constructed to provide for a maximumarea of contact between the liquid under pressure in the nozzle and theconvergent portions of the sheets. This form of nozzle designated 144,comprises a body 1146 providing a chamber 148 into which the liquid isintroduced under pressure. Body 146 includes a pair of flexible lips 150which are positioned against the surfacesof sheets 32 and 4-19 extendingaround and between pressure-applying rolls 4'2 and d4. Lips 150 extendonly slightly into the convergent passage between the rolls and define arelatively wide mouth 152 through which the liquid from chamberldfi isdispensed between convergent portions ofthe sheets 32' and 40 locatedwithin the bite of the rolls. The rolls themselves,being part of anapparatus designed for continuous operation, can be fixed againstmovement with respect to one another and the nozzle while lips of thenozzle are provided for the purpose of forming a liquid and air-tightseal between the nozzle and the sheets and do not function to seal thenozzle. The nozzle also includes end walls 154 which extend beyond thelongitudinal edges of the lips into the bite of the rolls for preventingescape of the liquid from between the sheets at their lateral edges.

It is apparent that the pressure exerted on the liquid is required to dothe work involved in feeding the liquid to the nozzle and advancing thesheet; and that the work involved in advancing the sheet is expendedprimarily in overcoming friction between the sheets and the apparatusand between components of the apparatus which are moved by the sheets.The energy expended feeding the liquid, from the container in which itis stored, to the nozzle is a function of the viscosity of the liquidand can be minimized by employing a liquid having the lowest possibleviscosity. Of course, the friction between the sheets and apparatus andbetween components of the apparatus should be reduced as much aspossible in order to minimize the energy required to be imparted to theliquid as compressive pressure. It is contemplated that in someembodiments of the apparatus, the frictional forces may be so great thatthey cannot be entirely overcome by pressure on the fluid alone, and itmay be necessary to provide mechanical means for assisting the fluid toadvance the sheets. For example, a motor of some type (e.g., a springmotor) might be provided for continuously applying torque to thepressure-applying rolls, which torque is insufficient in itself toadvance the sheets, but which assists in overcoming the frictionalforces resisting sheet movement. In such an embodiment, sheet movementwould be effected and controlled by a flow of the processing liquid inthe manner described, with the motor, in effect, merely reducingfrictional resistance to sheet movement.

The invention contemplates additional forms of juxtaposedpressure-applying members as well as modified types of nozzles and othermeans for feeding the liquid to the nozzle under pressure. Many of theseadditional types of pressure-applying members are shown and described inthe aforementioned US. Patent No. 3,142,243 and include, for example,juxtaposed members which do not rotate, but may be fixed with respect toone another and/or moved with respect to one another in differentmanners between liquid-spreading and nozzlesealing positions. Thenozzles hereto incorporating flexible lips may take a number ofdifferent forms which adapt them to use with the particular type ofpressureapplying members being employed. As for feeding the liquid tothe nozzle under pressure, this may be accomplished in a number ofdifferent ways including, for example, compressing a flexible liquidcontainer, employing gas pressure to empty the container, and pumpingthe liquid from the container to the nozzle. In each embodiment,however, sheet movement is effected by the liquid itself and iscontrolled by the pressure on the liquid at the nozzle which, in turn,is controlled by a valve or the means for pressurizing the liquid.

Since certain changes may be made in the above processes withoutdeparting from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:

1. In the treatment of a photographic sheet with a liquid distributed ina layer in contact with said sheet, the method comprising:

guiding said photographic sheet and a second sheet along convergentpaths into superposition with one another between a pair of membershaving opposed surfaces defining said paths and supporting superposedportions of said sheets against movement apart w from one another withsaid superposed portions disposed a predetermined distance apart;supporting a nozzle, having a discharge mouth bounded by a pair of lipswhich are at least equal in length to the width of the area of saidsheets to be treated, between said convergent portions of said sheetsand holding said lips in substantially liquid-tight contact with saidconvergent portions of said sheets; and

introducing a viscous photographic processing liquid through said nozzlebetween said lips into contact with the adjacent surfaces of saidsheets, said liquid being introduced under pressure sufficient to causethe movement of said sheets along said convergent paths past said lipsinto superposition between said members in the direction of flow of saidliquid between said lips.

2. A method of photography as defined in claim 1 in which said liquid iscontained under pressure in an extended elastic container coupled withsaid nozzle, a force is applied to said sheets tending, but insufficientby itself, to move said sheets in the direction of flow of said liquidfrom said mouth, and movement of said sheets is commenced and arrested,respectively, by commencing and arresting the flow of said liquid fromsaid container to said nozzle.

3. The method of producing a visible photographic im age comprising:

positioning a photographic image-recording sheet within photographicapparatus with a first portion of said sheet located in position forexposure and another portion of said sheet located between a pair ofmembers having opposed surfaces converging to a gap of a predeterminedwidth;

supporting said other portion of said image-recording sheet against oneof said surfaces;

supporting a portion of a second sheet against the other of saidsurfaces;

positioning a nozzle, having a discharge mouth bounded by a pair of lipswhich are at least equal in length to the width of said first portion ofsaid image-recording sheet to be exposed, between convergent portions ofsaid sheets between said members, and holding said lips in substantiallyliquid-tight contact with the opposed surfaces of said convergentportions of said sheets supported on said surfaces of said members;

exposing said first portion of said image-recording sheet to actiniclight;

introducing a viscous photographic liquid, including reagents capable ofreacting with said image-recording sheet following exposure thereof toproduce a visible Image in said sheet, through said nozzle between saidlips into contact with said opposed surfaces of said sheets;

exerting pressure on said liquid within said nozzle sufficient to causethe movment of said sheets through said apparatus past said lips betweensaid members in the direction of flow said liquid between said lips;

continuing to introduce said liquid under pressure through said nozzleinto contact with said sheets until said first portion of saidimage-recording sheet has been advanced into superposition with aportion of said second sheet and has moved through said gap; and

reducing the pressure exerted on said fluid within said nozzle aftersaid first portion of said sheet has passed through said gap betweensaid members.

4. A method of photography as defined in claim 3 in which said lips arepressed against one another simultaneously with the reduction ofpressure on said liquid to close said mouth and prevent the flow of saidliquid from said mouth.

. 1 l i '5. A method of photography as defined in claim 4 in which saidlips are pressed against one another by moving at least one of saidmembers relative to said nozzle.

6. In photography, the method of advancing a pair of sheets intosuperposition and treating said sheets with a liquid distributed in alayer therebetween, said method posed portions disposed a predetermineddistance apart; I V locating a nozzle, having a discharge mouth boundedby lips which are at least equal in length to the width of the area ofsaid sheets to be treated, between said convergent portions of saidsheets and holding said lips in substantially liquid-tight contact withsaid sheets; introducing a viscous photographic processing liquidthrough said nozzle between said lips into contact with adjacentsurfaces of said sheets under pressure sufficient to cause the movementof said sheets along said convergent pathspast said lips and intosuperposition in the direction of flow of said liquid between said lips;and applying torque to said roll tending to move said sheets in thedirection of flow of said'liquid between said lips, said torque beinginsufficient by itself to cause movement of said sheets relative to andbetween said members. p I 7. A method of photography. as defined inclaim 1 in which said liquid'is contained under pressure in an extendedelastic container. coupled with said nozzle, a force is applied to saidsheet by moving one of said members in engagement with one of saidsheets, said force tending but being insuflicient by itself to move saidsheets in the direction of flow of said liquid from said mouth.

8. In the treatment of a photographic sheet with a liquid distributed ina layer in contact with said sheet, the method comprising:

guiding said photographic sheet and a second sheet along convergentpaths into superposition with one another between a pair of membershaving opposed surfaces defining said paths and supporting superposedportions of said sheets against movement apart from one another withsaid superposed portions dis posed a predetermined distance apart;supporting a nozzle, having a discharge mouth bounded by a pair of lipswhich are at least equal in length to the width of the area of saidsheets to be treated, between said convergent portions of said sheetsand holding said lips in substantially liquid-tight contact with saidconvergent portions of said sheets;

' introducing a photographic processing liquid through said nozzlebetween said lips into contact with the adjacent surfaces of saidsheets, said liquid being introduced under pressure sufiicient to causethe movement of said sheets along said convergent paths past said lipsinto superposition between said members in the direction of flow of saidliquid between said lips;

said liquid being fed to said nozzle under pressure and movement of saidsheets being arrested by reducing the pressure on said liquid withinsaid nozzle; and

simultaneously with the reduction of pressure on said liquid within saidnozzle, pressing said lips against one another to close said mouth andprevent flow of said liquid from said mouth.

References Cited by the Examiner UNITED STATES PATENTS 1,161,346 11/15Schmidt 2647 8/50 Land 95-13 NORTON ANSI-1BR, Primary Examiner.

40 JOHN M. HORAN, Examiner.

1. IN THE TREATMENT OF A PHOTOGRAPHIC SHEET WITH A LIQUID DISTRIBUTED INA LAYER IN CONTACT WITH SAID SHEET, THE METHOD COMPRISING: GUIDING SAIDPHOTOGRAPHIC SHEET AND A SECOND SHEET ALONG CONVERGENT PATHS INTOSUPERPOSITION WITH ONE ANOTHER BETWEEN A PAIR OF MEMBERS HAVING OPPOSEDSURFACES DEFINING SAID PATHS AND SUPPORTING SUPERPOSED PORTIONS OF SAIDSHEETS AGAINST MOVEMENT APART FROM ONE NOTHER WITH SAID SUPERPOSEDPORTIONS DISPOSED A PREDETERMINED DISTANCE APART; SUPPORTING A NOZZLE,HAVING A DISCHARGE MOUTH BOUNDED BY A PAIR OF LIPS WHICH ARE AT LEASTEQUAL IN LENGTH TO THE WIDTH OF THE AREA OF SAID SHEETS TO BE TREATED,BETWEEN SAID CONVERGENT PORTIONS OF SAID SHEETS AND HOLDING SAID LIPS INSUBSTANTAILLY LIQUID-TIGHT CONTACT WITH SAID CONVERGENT PORTIONS OF SAIDSHEETS; AND INTRODUCING A VISCOUS PHOTOGRAPHIC PROCESSING LIQUID THROUGHSAID NOZZLE BETWEEN SAID LIPS INTO CONTACT WITH THE ADJACENT SURFACES OFSAID SHEETS, SAID LIQUID BEING INTRODUCED UNDER PRESSURE SUFFICIENT TOCAUSE THE MOVEMENT OF SAID SHEETS ALONG SAID CONVERGENT PATHS PAST SAIDLIPS INTO SUPERPOSITION BETWEEN SAID MEMBERS IN THE DIRECTION OF FLOW OFSAID LIQUID BETWEEN SAID LIPS.